I have been doing some research, and one that captures most of my attention is Gentoo. Any opinions ?

I'm using an old Gateway 3.0ghz with 1gb of ram and 126mb of video(which should be irrelevant for my use)

Well yes, gentoo is a good idea for performance distro, but it takes a while till you compile all the packages and configure everything, however there is also great performing distro called Archlinux it has great and friendly community, rich wiki (there are answers for nearly all the problems you might face, also alot of how-to's) and it has package manager called "pacman" and it is simple to use. Packages there, are optimized for i686 that means this distro will perform almost as fast as a gentoo.

conclusion, you can go for gentoo, probably you would get best performing distro there is, if you are not afraid to spend some sleepless nights for it

and if you got less time, i advise to go for Archlinux.

I agree with Affromen. I was able to compile my current gentoo in my 4yo 2.8G box with the cflags "-march=pentium4 -O3 -fomit-frame-pointer -funroll-loops -pipe" with no problem. I got great speed advantages at least compared to my current slackware.

...just remember that there is probably more difference in what and how you configure than in choice of distro, per se.

Thanks for the replies,
Time is not problem for me as long as the outcome pays off.
there are 2 things i would like to have easy control off the bat.
1. the firewall, since i will probably be setting up a webserver, along with MySQL, alot of interaction between remote users using the website to alter the game's database.
2. While compiling the game server i might need a handful of libraries, does gentoo or archlinux have any repositories like debian or redhat so i don't have to go all over the internet looking for libraries?

While compiling the game server i might need a handful of libraries, does gentoo or archlinux have any repositories like debian or redhat so i don't have to go all over the internet looking for libraries?
Do you mean gentoo's portage system? checkout http://packages.gentoo.org. It's pretty complete already for every main package you need to install. For example, when compiling mozilla-firefox, every library that you'll need should be already there. And just in case you find a library that does not exist, you can build your own ebuild. I don't know anything about archlinux though but it's not bad to try it too.

Use debian, it might even be faster than arch:

http://bbs.archlinux.org/viewtopic.php?id=44716


Or CentOS